Which is the best twilight book and why?

I have finished reading the twilight series and my personal favourite book is new moon .So i would like to know about your personal favourite book and also the least favourite book of the twilight saga

I would have to say New Moon too. I love the part where Edward comes back to Bella it's soo sweet and the volturi as there is more about them in the book than the film. I don't really have a least favourite because I love them all!!